[petuniasevan]

once covered by giant trees known as metasequoias

We don't have plants that can survive under those conditions today

You've got to be joking. Either this woman is a moron, or she thinks she can fool everyone.
Metasequoias, otherwise known as Water Pines, can be found in a remote area in China TO THIS DAY.
You can even buy them from specialty nurseries on the West Coast.
They are DECIDUOUS conifers, like their relatives the bald cypresses, and unlike the true sequoia and redwood.

I'll bet they don't mind 4 months of darkness, during their dormant phase.

[blam]

"They are DECIDUOUS conifers, like their relatives the bald cypresses, and unlike the true sequoia and redwood. "

Yup. My bald cypresses are just beginning to put on their spring needles/leaves. (They've been bare all winter)

[RightWhale]

The living fossil, a hot topic in paleobotany:

Hu, Hsen-Hsu and Wan-Chun, Cheng 1948. On the new family Metasequoia and on Metasequoia glyptostroboides, a living species of the genus Metasequoia found in Szechuan and Hupeh. Bull. Fan Mem. lnst. Biol. New Ser. 1(2): 153-161 (English, Chinese summary). [This is the original taxonomic description of the living Metasequoia glyptostroboides].